The way we write code is changing. No longer do most developers spend the bulk of their time creating new code from scratch. Instead, they largely combine existing open source code, third-party APIs, and other off-the-shelf bits to create new products. This shift from “build” to “assemble” has created a demand for entirely new tools and workflows.

Runnable (fka, CodeNow) launched into public beta less than one month ago to provide developers a central hub for easily finding and implementing reusable code and make it executable within a Web-based environment. Today, the company announced the close of a $2 million Seed round led by Sierra Ventures, with participation from Resolute.VC, Angel Pad, 500 startups, KISSmetrics founder Hiten Shah, and Makara and StrongLoop founder Issac Roth.

The Palo Alto-based startup has partnered with several dozen companies – with another 150 more on its wait list according to co-founder and CEO Yash Kumar – to include their APIs (application programming interface), libraries, SDKs (software development kits), and other resources on the platform. The company hopes to open up the floodgates fully by January.

“It’s all about the content, and we know that,” Kumar says. “We can create a win-win by offering developers a robust catalog of code, while at the same time offering companies a forum to promote their APIs and products.”

Prior to Runnable, the market for off-the-shelf code was heavily fragmented, with content spread across developer blogs, community and company documentation sites, Stack Overflow, GitHub, and many other channels. As a result, in today’s "assemble versus build" environment, developers must spend as much time searching for code, and reading lengthy documentation on its implementation, as they do actually implementing it in their own products. Runnable aims to eliminate much of this wasted time by centralizing the best code resources in a single platform.

The vision for Runnable came to Kumar during his time working as a software engineer within Amazon. Even in that large and enormously productive organization, inordinate amounts of time is being wasted searching through the company thousands of proprietary APIs, he says – hundreds of which would be incorporated into the typical project.

Runnable is not the first online code repository or developer community to be created. GitHub and StackOverflow are well established and have solved dozens of recurring problems for developers and technology companies. But none of these existing solutions addresses the discoverability issue, and that’s where Runnable hopes to create value.

Beyond discoverability, Runnable offers developers a Web-based environment in which this code can be executed – which is by no means an easy task.

“A picture is worth a thousand words, as they say, and it’s the same thing with seeing a piece of code running,” Kumar says. “That’s why this it’s always been a key piece of our vision from the beginning to allow developers to execute within our platform.”

The company does this by spinning up a dedicated virtual machine instance for each developer and installing any necessary dependencies such as Apache and relevant APIs. Companies can upload their existing SDKs into Runnable and fork an instance of their existing code-based into the platform for testing. None of this would have been possible as recently as three years ago, according Kumar, simply by virtue of the dramatic reduction in cost of providing the computer memory necessary to run programs in the cloud.

The majority of Runnable’s self-described “considerable traffic” to date has come from organic sources. The company’s name – which changed from the aforementioned CodeNow – adds some serious SEO juice, according to Kumar, as developers regularly search for “runnable code.”

Runnable is free to use today, and the company has no plans to focus on monetization in the near term, according to its CEO. With just seven employees – although it plans to hire – and a fresh $2 million, it has sufficient runway to focus on growth and perfecting the user experience for the near term.

“Eventually, like in most things, if you provide a valuable service – in this case to the developer ecosystem – then monetization comes naturally,” says Sierra’s Mark Fernandes. “We think this will prove to valuable to a large number of companies.”

By comparison, GitHub has been profitable from its earliest days. Runnable, should it choose to follow a similar enterprise-focused model, could presumably turn on monetization at any point and become similarly capital-efficient.

Asked about the risk of duplication, Fernandes seemed unconcerned. “I think the most overlooked aspect of this is how difficult it is to build,” he says. “We view Runnable as highly defensible. Their team is the best of the best when it comes to developer tools.”

The big risk, which Runnable can’t overcome today but which will one day serve as its greatest asset should it continue to grow rapidly, is that of network effects. Today, there is a limited code library on the platform and a minimal traffic from developers. GitHub and StackOverflow, for example have far more of each essential resource.

But if the company scales in line with its own expectations, it will have among the largest and best organized repositories of usable code and a community of developers eager for additional content. Should it reach that point, then it would be truly defensible.

Runnable appears to have stumbled on a much needed solution to a very real problem. The timing couldn’t be better, in terms of the shift in the way developers work and the availability of the underlying infrastructure required to run such a platform. The company has a long way left to go to solve the code discoverability problem. But it’s fair to say that Runnable the most compelling solution we’ve seen yet.